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Post by tacoman25 on May 7, 2009 13:28:43 GMT
UAH v RSS There appears to be an idea floating round that a significant difference exists between UAH and RSS datasets. This is total garbage. It's true there is a step change around 1992. Before 1992, RSS was cooler than UAH whereas since 1992 RSS has been warmer. It might be coincidence, but I wonder if the 'step' is related to the Pinatubo eruption in 1991. Whatever the reason, it almost certainly explains the difference in trends between UAH & RSS since 1979. I'm convinced that there is nothing that UAH & RSS are currently doing with respect to the various necessary data adjustments which is significantly altering the trend difference. To illustrate this, check out the UAH & RSS trends since 1992. www.woodfortrees.org/plot/uah/from:1992/to:2008/trend/plot/rss/from:1992/to:2008/trend I think that's what they call "parallel lines". Just to confirm the similarity in trends. Linear regression (since 1992) gives: UAH +0.22 deg per decade
RSS +0.22 deg per decade And just for good measure the surface trends since 1992: GISS +0.24 deg per decade
Hadley +0.20 deg per decade Can we now stop all the drivel about fiddling, fudging and other conspiracy nonsense. Magellan: don't let this distract from the WUWT article. Just keep in mind, those "decadal trends" since 1992 are inflated because 1992 was a very cool year thanks to Pinatubo. |
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Post by glc on May 7, 2009 14:26:33 GMT
Just keep in mind, those "decadal trends" since 1992 are inflated because 1992 was a very cool year thanks to Pinatubo. Yes I know. But that's not related to the point I'm trying to make which is to show that since 1992 RSS and UAH trends have been virtually identical. |
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Post by jimcripwell on May 13, 2009 18:57:03 GMT
GISSTEMP is in for April. 0.44 C. Average for the first 4 months of 2009, 0.46, the same as last year. I know all about the problems with GISSTEMP, but the warmaholics, e.g. RealClimate, use it, and when it shows global temperatures are falling, then there really is no argument.
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Post by tacoman25 on May 13, 2009 19:08:35 GMT
GISSTEMP is in for April. 0.44 C. Average for the first 4 months of 2009, 0.46, the same as last year. I know all about the problems with GISSTEMP, but the warmaholics, e.g. RealClimate, use it, and when it shows global temperatures are falling, then there really is no argument. Do you have a link to that data? Is that for both ocean and land? |
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Post by jimcripwell on May 13, 2009 20:41:58 GMT
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Post by kenfeldman on May 13, 2009 22:30:01 GMT
Except that this shows that global temperatures are rising. If it stays at 0.46 for the year, that would make it warmer than any year in the 19th and 20th centuries, except 1998, which was the year of the Super El Nino.
Where is the cooling? The solar forcing has been going down since the second peak of cycle 23 in 2002. The first spotless day of cycle 23 was in 2006, and we've been in a minimum for at least the past two years. We've had two La Ninas too and the PDO is negative!
So when is the global cooling all the deniers are warning us about going to happen? Something seems to be keeping the planet warm. I wonder if it could be a blanket of invisible gases in the atmosphere? Nah, that's just too weird to believe, even if the science demonstrating that it is occuring is a century and a half old. You can't trust scientists!
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Post by jimcripwell on May 14, 2009 0:20:29 GMT
kenfeldman writes "Where is the cooling?"
What you need to realize is that when you have a cooling trend, following a warming trend, then the cooling trend starts at the maximum of the warming trend. What as happened, as anyone can see if you fit a 4th order polynomial through the satellite temperature data, (or any of the 5 data sets for that matter), is that global temperatures peaked a few years ago, and passed through a shallow maximum. Now, temperatures are falling. Naturally, recent temperatures are well above what they were 20 or 30 years ago. But that does not mean that they are not now falling. What matters is the slope of the temperature/time graph as on now. For several months this slope has been negative. The longer it stays negative, the more temperatures will continue to fall. What warmaholics do is the force a linear fit to the data, which disguises the fact that temperatures are falling.
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Post by kenfeldman on May 14, 2009 0:23:38 GMT
A linear fit can give you an estimated rate of warming over a period of time, such as 0.2 degrees per decade. It can be easily calculated using least squares regression (and automatically done in a spreadsheet such as Excel).
What the heck does a 4th order polynomial fit represent?
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Post by tacoman25 on May 14, 2009 0:54:10 GMT
Except that this shows that global temperatures are rising. If it stays at 0.46 for the year, that would make it warmer than any year in the 19th and 20th centuries, except 1998, which was the year of the Super El Nino. Where is the cooling? The solar forcing has been going down since the second peak of cycle 23 in 2002. The first spotless day of cycle 23 was in 2006, and we've been in a minimum for at least the past two years. We've had two La Ninas too and the PDO is negative! So when is the global cooling all the deniers are warning us about going to happen? Something seems to be keeping the planet warm. I wonder if it could be a blanket of invisible gases in the atmosphere? Nah, that's just too weird to believe, even if the science demonstrating that it is occuring is a century and a half old. You can't trust scientists! Just because the global temperature is still warm in relation to previous centuries does not equal WARMING my friend. Thus far, there has been little or nor WARMING this decade/century. The IPCC model projections continue to fall further away from any reasonable confidence. And GISS/Hansen's prediction from 2007 that we would see a new global temp record in the next 2-3 years is not looking good. 2008 obviously fell way short, 2009 is not looking likely at all, and that just leaves 2010 as their only hope. No, there is no evidence of rapid cooling as some on here were predicting. But there is also no evidence of accelerating AGW. Learn to compromise and accept reality. |
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Post by woodstove on May 14, 2009 3:29:10 GMT
Except that this shows that global temperatures are rising. If it stays at 0.46 for the year, that would make it warmer than any year in the 19th and 20th centuries, except 1998, which was the year of the Super El Nino. Where is the cooling? The solar forcing has been going down since the second peak of cycle 23 in 2002. The first spotless day of cycle 23 was in 2006, and we've been in a minimum for at least the past two years. We've had two La Ninas too and the PDO is negative! So when is the global cooling all the deniers are warning us about going to happen? Something seems to be keeping the planet warm. I wonder if it could be a blanket of invisible gases in the atmosphere? Nah, that's just too weird to believe, even if the science demonstrating that it is occuring is a century and a half old. You can't trust scientists! Speaking of a century and a half old, did manmade co2 get us out of the Little Ice Age? Not even Hansen et al. make that claim. And, if not, how do you purport to explain how the "baton" of warming was handed from a mystery power to co2 in, say, 1975? I hope someone took a photo of this momentous event.  |
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Post by magellan on May 14, 2009 3:44:52 GMT
A linear fit can give you an estimated rate of warming over a period of time, such as 0.2 degrees per decade. It can be easily calculated using least squares regression (and automatically done in a spreadsheet such as Excel). What the heck does a 4th order polynomial fit represent? Analyzing temperature data using a "linear fit" is neither linear, nor does it fit. |
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Post by poitsplace on May 14, 2009 4:33:51 GMT
Except that this shows that global temperatures are rising. If it stays at 0.46 for the year, that would make it warmer than any year in the 19th and 20th centuries, except 1998, which was the year of the Super El Nino. Where is the cooling? The solar forcing has been going down since the second peak of cycle 23 in 2002. The first spotless day of cycle 23 was in 2006, and we've been in a minimum for at least the past two years. We've had two La Ninas too and the PDO is negative! So when is the global cooling all the deniers are warning us about going to happen? Something seems to be keeping the planet warm. I wonder if it could be a blanket of invisible gases in the atmosphere? Nah, that's just too weird to believe, even if the science demonstrating that it is occuring is a century and a half old. You can't trust scientists! Speaking of a century and a half old, did manmade co2 get us out of the Little Ice Age? Not even Hansen et al. make that claim. And, if not, how do you purport to explain how the "baton" of warming was handed from a mystery power to co2 in, say, 1975? I hope someone took a photo of this momentous event. Between the failed models and recent cooling, it's obvious that planning for anything but the OBSERVED rate of warming is probably a bad idea. I find it sad and a little disturbing that this field of "science" has been degraded to the point that those using the OBSERVED rates are often considered "deniers". |
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Post by donmartin on May 14, 2009 6:44:07 GMT
I think a "least squares" or statistical regression is utilized in order to eliminate anomalies and threshold events. Were the human race to disappear this instant from an asteroid strike, a population prediction on the basis of a statistical regression model made 5 minutes before would indicate that ten years from now, population would be exponentially increasing, and the asteroid strike would not be recorded: simply because an asteroid strike was not included in the parameters. Current climate models apparently ignore glaciation and timing parameters which provide for precipitous climate anomalies.
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Post by jimcripwell on May 14, 2009 10:59:36 GMT
kenfeldman writes "What the heck does a 4th order polynomial fit represent? "
Sorry, I wrote that very badly. In order to assess the trend over the full range of temperature measurements, the standard technique is to use least squares regression analysis. The best fit for the current world temperature data is non-linear. The best of these non-linear equations is some form of polynomial; in this case a fourth order polynomial. This is the best fit to what is happening to world temperatures. Pleaase note that this type of analysis has no predictive capabilities.
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Post by neilhamp on May 15, 2009 16:56:37 GMT
GISSTEMP anomoly data for the first 4 months of each year
1998 0.60
1999 0.38*
2000 0.42*
2001 0.43*
2002 0.71
2003 0.53
2004 0.55
2005 0.64
2006 0.52
2007 0.68
2008 0.37*
2009 0.46
So far, 2009 is cooler than 6 out of the last 7 years
0.14 degrees below the 2002/7 mean
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